I just bought a five gallon cooler (rubbermaid cylinder type) and plan to convert it into a mash tun. The existing tap was easy to remove and now I have to decide on the materials to use for the new valve tap. Brass fittings are easy to come by but I've heard that these can contribute bad flavors. Can anyone confirm this? What about plastic fittings? And does anyone have an easy way of constructing a sparging assembly? Do I need a sparge assembly?

"...materials to use for the new valve tap. Brass fittings ... but I've heard that these can contribute bad flavors"

A: Most of the causes for off flavors via brass are caused by cleaning them with abrasives and not letting the fittings re-oxidize (passivate) before use. But really... the volume of liquid versus the surface area of the fitting should not result in the producion of noticable flavors in the finished product. Just never use copper for this application due to the acidic nature of wort, it can leach metallic flavors into the product due to the prolonged exposure time during mashing and runoff.

"What about plastic fittings?"

A: Definitly not a good idea. Unless using hi-temp, chemically resistant plastics, they will eventually leak. They are also susceptable to scratching. After every cleaning, they become more and more difficult to remove any accumulations without damage. Eventually you have to throw them away.

"...does anyone have an easy way of constructing a sparging assembly?"

A: Yes... you can buy soft copper coil and bend it in a spiral, drill 5/16" holes at spaced intervals to evenly hydrate the grain bed in drips and cap the end near the center. However, the cost of the coil, the effectiveness of the ring and the pain of making it are not worth it. The best design available to homebrewers is made by Listermann Mfg. and is called Phil's Sparger. It is modeled exactly as my 20 bbl. mash tun sparge arm is. When brewing at home I use a Phil's. It spins slowly like a helicopter blade, gently sprinkling the bed without disrupting it. It is powered simply by water pressure generated by gravity from a sparge kettle valve. This device is only about $17 ! Very close to the coil and fitting cost without even considering the pain of making it.

"Do I need a sparge assembly?"

A: No if you want to make 2~3 gallon batches. If you don't want to sparge and want a 5 gallon yield, get the 10 gallon cooler and mash the whole volume in that. There are technical as well as time and energy advantages to this technique: 1) Time: Don't have to heat water separately for sparge, don't have to wait during runoff time; 2) Money: Don't need an extra vessel to heat sparge water while collecting wort runnings in primary kettle; 3) Flavor: Since you will not run the risk of leaching tannins into the wort via high temperature and high pH (>6) sparge water. The only limitations I'm aware of on this one is that it is hard to get the right amount of water and grain in the cooler for high gravity mashing at full volume. A solution to this is to produce a concentrated gravity wort and dilute in the kettle, although this raises the pH of the boil unless you acidify (lower pH) of the topping water or adjust the resulting pre-boiled wort.